This invention relates to decontamination and sterilization devices and, more particularly, to a method and apparatus for sterilizing articles of mail that may be tainted with anthrax or other pathogens.
A single letter contaminated with anthrax or similar pathogens can cause serious health issues or even death to humans. In fact, a single letter may include thousands of times more than the lethal dose of anthrax. The threat of safety relative to the delivery of mail was accented by the anthrax infections following the historic terrorist attacks against the United States on Sep. 11, 2001. Several people were infected with anthrax as a result of letters containing the deadly pathogens. Postal offices and other businesses had to be shut down and fully sterilized. Anthrax in a single letter can cross-contaminate other articles of mail, postal sorting equipment, and the like. This is a significant problem in view of the 680 million pieces of mail handled by the U.S. Postal Service every day.
Various devices have been proposed for sterilizing medical equipment and other articles. Although assumably effective for their intended purposes, the existing devices are not suitable for sterilizing mail at the initial point of mail deposit or without damaging the mail. More particularly, the use of steam heat or intense dry heat would irreversibly damage mail. Further, chemical sterilization with ethylene oxide gas avoids the damages associated with heat sterilization but requires long cycle times and the handling of harsh chemicals. These disadvantages would be unacceptable for use in mass mail processing. Sterilization with gamma radiation, while effective, would be prohibitively expensive for use in the decentralized mail processing and delivery industry.
Therefore, it is desirable to have a method and apparatus for sterilizing mail quickly and without damaging the mail. Further, it is desirable to have a method and apparatus for sterilizing mail without generating excessive heat or pollution. In addition, it is desirable to have a method and apparatus for sterilizing mail that may be used in the mail sorting process.